This invention relates to a shoe with a liner inserted during formation of the shell (in this description the body of the shoe, less the liner, sole, and any other part not formed as a unit with the body, is referred to as the shell), and more particularly to a shoe with a synthetic resin shell that can prevent the shape of the shoe from collapsing.
A shoe with part, or all of its shell molded from synthetic resin has features unattainable with a shoe sewn from leather or cloth. Namely, the construction of this shoe does not entail cutting flat pieces of material from a sheet and shaping them in three dimensions to follow the contour of the foot, but rather the shell of the shoe is formed into a three dimensional shape using a mold. Therefore, this shoe has the features that it is "broken in" from the first wearing, and it can be worn in comfort, even for long periods, without fatigue. Another feature of the shoe having this construction is that the labor of working with sheet material for the shell is unnecessary, and the shoe is extremely easy to produce in quantity.
Although the solid shell having curved surfaces formed by molding collapses little compared with shells made of leather or cloth, the opening for foot entry gradually widens with wear. This can be reduced by making the synthetic resin shell thicker. However, a shoe with a thick shell has the drawback that it is heavy and wearing comfort is reduced.
The present invention was developed to overcome this drawback.
It is thus a primary object of the present invention to provide a shoe that prevents collapse of the shell over long periods.
It is yet another primary object of the present invention to provide a shoe that has a thin, light shell that can prevent collapse of its shape.
It is a further primary object of the present invention to provide a shoe that is easily produced in quantity without the use of a special process to heat a hot-melt bond (a synthetic resin adhesive with rigidity), but rather to heat the hot-melt bond with molten synthetic resin at the same time the shell is molded. This forms the shell with support and retention of the liner at the same time.